West German patent DE-GM 83 27 001 describes a steerable skateboard with a supporting platform; with one front and rear axle, each mounted at a right angle to the underside of the supporting platform; with the axles bearing a set of front wheels and rear wheels, respectively; and with a wheel hub firmly attached to the rear wheel set. The skateboard includes an acceleration device which consists of a spring and a traction rope. Except for a portion at the rear of the skateboard, the supporting platform is level. A small steering platform in the front of the supporting platform serves as steering device and, like the supporting platform itself, is positioned horizontally.
A disadvantage of the steerable skateboard of West German patent DE-GM 83 27 001 is that it leaves the skateboard rider with poor stability. In addition, only one guide roller for one traction rope is mounted at a location in front of the drive wheel. Consequently, one can only operate one traction rope with one hand, or hold onto it with both hands at the same time. This prevents riding in an optimal or comfortable position, both while operating the traction rope or otherwise. With the disclosed steerable skateboard, the rider has to bend slightly forward in order to use both hands, and must pull the rope upward in front of the stomach. This is generally very inefficient, in part because this position puts undue strain on the lower back.
The swivel axis of the foot support is also positioned inefficiently. The surface of the foot support and the front leg of the rider do not meet at a right angle, or along the rider's swivel axis. For this reason, in order to steer, the rider not only has to turn his leg, but also has to bend his foot along two axes if he wishes to keep his foot on the foot support while making a turn. Due to the limited flexibility of the ankle, a rider can only bend his foot in this way under a small range of circumstances. Riding a skateboard in this manner is inefficient, and is preceived as uncomfortable.